<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>

<div id="app">
  <ul>
    <!-- 提高内部性能 -->
    <li v-for="item in letters" :key="item">{{item}}</li>
  </ul>
</div>

<script src="../js/vue.js"></script>
<script>
  const app = new Vue(
    {
      el: '#app',
      data:
      {
        letters:
        [
          'A',
          'B',
          'C',
          'D',
          'E'
        ]
      }
    }
  )
</script>
  
</body>
</html>